Recoil buffer for cutter bars



Feb. 9, 1932. N B, STQNE 1,844,188

RECOIL BUFFER FOR'CUTTER BARS Filed March 27, 1929 Gttoruegs.

Patented Feb. 9, 1932 tenses NATHANTEL B, STONE, oF wAsHmeToN, :DISTRICTor' ooLUMBrA RECOIL'BUFFER FOR CUTTER BARS Y Application led March y27,1929. Serial No. 350,257.

This invention relates to buffers for the reciprocating cutter bars ofmowing machines, and, among other objects, aims to provide a relativelysimple and efficient double-acting recoil device that can easily beattached to or built on a machine. The main idea is to elimina-te to agreat extent the concussion and resultant destructive shocks which occurat the ends of the pitman strokes and to utilize the power delivered tothe recoil device to overcome the inertia of the blade and start it onits return stroke. f

In the accompanying drawings Fig. 1 is a top plan view, parts beingbroken away, showing the preferred embodiment of the device applied tothe shoe on a.

finger bar;

Fig. 2 is a longitudinal section through the recoil device shownv inFig. 1; and FF ig. 3 is a section taken on the line 3-3 of Referringparticularly tothe drawings, the improved recoil buer is shown as beingsecured above the shoe 10 on a finger bar 11 of a conventional mower,the cutter bar `12 having a head 13 guided in a channel guide 14. Insuch conventional designs of mowers the pitman 15 is bifnrcated and isconnected to the head and the length of the stroke is such that theopposite ends of the cutterhead are projected slightly beyond the openends of the channel guide, which is covered by the usual or a specialcover plate 16.

The illustrated example of the recoil def vice is here shown asincluding a. pair of spring-urged rockable levers 17 carried by av frame18, and the arrangement being such that the lower ends of the leversproject into the path of the cutter head 13 so that the head will strikethem justbefore it reaches Also, these flanges limit the inward swingingor rocking movement of the levers 17.

In Fig. 2, the right end of theframe is shown ashaving a projecting lug21 which provides a fulcrum for the lever, the lever preferably beingstamped out of sheet metal and presenting a depression or channel 22cooperating` with the projection. The upper end of the lever at theopposite end of the frame,islikewise provided with a channel which isrockably mounted on a projecting end 23 of a channel plate=211 removablysecured to the Vupper flange of the T-shaped frame.

To permit the plate to slide to the right so that the levers andassociated elements may be assembled or dismantled,` the channelshapedplate is constructed to slide longitudinally on the upper. iange of theframe as shown in Fig. 2,' and has a T-'shaped groove which prevents itfrom being disengaged. It is adapted to be'locked in extended positionto tension the springs by any suitable means such as the spring? plunger25seated in the upper flange of the frame member and arranged to snapinto a hole in' the plate.

In the present example, two strong coll springs 26 are connected to theplate levers normally to urge them inwardly. At one -end of the springs-a VLl-shaped bar 27 having 80 hooked ends 24.8k 'detachably` engagingthe radially bentends of the springs, is shown as extending across thelever 17 below its fulcrum. Herein, the plate lever has a diestampeddepression 29 providing a bearing 85 for the U-shaped bar 27. Theopposite ends of the coil springs are shown as being connected to theother lever by means of hooks 30 having screw threaded Shanks passingthrough threaded openingsV in a crossbar 31 90 which is seat-ed in thebearing depression 29 in the lever. y

This arangement is such that the hooks may be turned to engage ordisengage the radially bent ends of the springs and also be adjusted totension the springs properly.

Referring to Figs. 1 and 2, the plate levers are there shown as having apowerful leverage which permits their lower ends to move or swingthrough an appreciable distance without expanding or stretching thesprings more than a small fraction of that distance. This prevents thepowerful springs from being stretched beyond their elast-ic limits andobviates quick breakage by premature crystallization. Furthermore, theplate levers are preferably bulgedjor dished outwardly near theirlowerends as shown in Fig. ,2 to add to their strength or bending resistance,it being understood that they are subjected to powerful hainmei'blows.Also the bearing depressions in the levers are closed at their ends toprevent lateral displacement of the levers with respect to the frame. c

To assemble the springs and'levers on the vframe, the channel plate Misslid to the right as viewed-in Figs. land 2;-each'lever is set in place;the two springs are hooked on the 4U-shaped bar; the crossbar 31 isplaced in its seat; and the hooks 30 are-turned bypliers or arsuit'abletool to engage `the ends ofthe coils. This is easily done because thesprings are not under tension.

As best shown in Fig. 2, a lever32 is adapted'to vbe inserted `throughanopening 33 in thechannel plate and into an opening-34 in the frame jTheleverisusedto 'force the rchannel plate to its kextended position, whenthe-spring latch or button will snap in place and lock it. It will beunderstood that the lever is also used to relievethe pressure on thebutton when it -is desired to depress the button and release the lockingconnection.

To Iprev-ent grass, grain sta ks, etc, `trom becoming entangled in themechanism, a

sheet metal hood or cover 35 is :removably mounted over it. Herein,thecover is fastened by means of a slotted flange vwhich engages a stud37 o nftheshoe 10 and a spring urged latch hook88 engages in the opening33 of the channel plate. To remove the hood -itis only .fnecessaryftoforce it lto the right vas Vviewed in Fig. V3 imtil the slotted :foot

disengages the stud 37 and then lift iU orf.

Obviously, any other suitable latch means maybe employed. It `will beobservedthat ithe front, top wall of the -hood vis -inclined upwardlyand rearwardly to vpermit the cut grass, grain, etc., to slide over it.e

VIt is necessary occasionally to remove the .cutting blade 12 for`sharpening-and repairs.

For this purpose the rear lever plate 17 has to be. swung out lofthepath of the cutter head "13. Thiscan Vbe very quickly accomplished lbyrelieving the spring tension las hereinbeforedescribed, so'that'thelever is tree to swing.

F rom'the 'foregoing description; it will be seenthat `the improvedrecoil buffer is very compactand may be installedon old'as well as newmachines without requiring any eX pensive alterations. It is so arrangedthat it does not become clogged up. The springs have adequate strength'to absorb the shock of Tthe cutter `head and relieve all of theconnectedto both of said levers.

means to adjust the pressure of said spring.

moving parts of the destructive stresses to which they are usuallysubjected. They overcome the inertia of rest at each end of the bladestroke and thereby relieve the pitinan crank pin of tremendous shearingstrain as well as wear. Moreover, buffer action materiallyreduces thenoises of the reciprocating Athe invention be Vused conjointly, sincethey may be employed advantageously in various combinations andsubcombinations.

-What I claim is v 1. In combination with a reciprocating cutter barhaving a head, a frame member Xed on a inger bai' over the head; twoleversrockably lmounted on the frame and projecting into the path of thehead; and a double-acting spring operatively connected toboth levers.

2. A recoil buer for cutter bars comprising incombination, a framemember above the cutter bar; vertical levers rockably mounted on theframe and projecting into the path ofa Xed member onthe cutter bar; anda pair of tension springs each operatively 3. In combination vwith amower, a doubleacting recoil device on the shoe lcomprising a framemember secured to the top ofthe shoe a pair of vertical levers rockablymountved. on the frame member and-having their free ends projecting intothe path of thefcutter head near each end of its stroke; a tensionspring operatively connected to both of said levers below their rockingconnections; and

4. In combination with a mower, a doubleacting recoil device on theshoecomprising a `frame member secured to the top of the .shoe above thecutter head; a pair of relative- Yly short levers rockably mounted onthe frame member and having their free ends projecting into the path ofthe cutter head near each end of its stroke; a pair of tension springsconnected to both of said levers and means to adjust the tension of thesprings.

5. In combination with a mower, a doubleacting recoil buffer comprisinga fram-e having a base secured to the upper side of the shoe; a pair oflevers rockably and loosely mounted on the frame and projecting in thepath of the cutter head; a pair of coilsprings connected to both of saidlevers; means to relieve the tension of the springs; and means to adjustthe tension on the levers.

6. In combination with a mower, a doublewardly in the path of the cutterhead; a pair of coil springs connected to the levers; means to relievethe tension of the springs; stop means for the levers on the base tolimit the inward rocking movement of the levers; and means to adjust thetension on the levers.

7. A double-acting recoil device for the cutter blades of mowerscomprising in combination a substantially T-shaped frame member having abase flange secured to the top of the mower shoe; a pair of die-stampedlevers mounted on the Jframe member and projecting into the path of thecutter head; stop means on said base flange for said levers; springsoperatively connected to said levers; means to adjust the tension ofsaid springs; and means to relieve the levers of the tension of saidsprings whereby the cutter bar may be removed.

8. A double-acting recoil device for the cutter blades of mowerscomprising in combination a substantially T-shaped frame member having abase flange secured to the mower shoe; a pair of die-stamped leversmounted on the frame member and projecting into the path of the cutterhead; stop means on said base flange for said levers; springsoperatively connected to said levers; means to adjust the tension ofsaid springs; a channel-shaped plate member slidably mounted on saidT-shaped frame member and providing a fulcrum for one of said levers;means to lock the said plate member in extended position to place saidsprings under tension; and means to release the plate member and there*by relieve the spring tension on said levers whereby one of the leversmay be swung out of the path of the cutter head to permit the cutter barto be removed.

9. A double-acting recoil device for the cutter blades of mowerscomprising in combination; a substantially xiV-shaped frame memberhaving a base flange secured to the mower shoe; a pair of die-stampedlevers mountedon the frame member and projecting into the path of thecutter head; stop means on said base flange for said levers; a pair ofcoil springs on opposite sides of said frame member; bars having hookmembers connecting said springs to said levers, one pair of heck membershaving screw threaded shanls to permit adj nstment whereby to regulatethe tension of said springs; and means to relieve the levers ofthetension of said springs whereby the cutter bar may be removed.

l0. A double-acting recoil buder for mowing machine cutter barscomprising, in combination7 a substantially l'shaped frame membersecured to the shoe above the cutter head guide; a projection at one endof the frame member providing a fulcrum; a diestainped sheet metal leverhaving a depression seated on said fulcrum; a channel-shaped memberslidably connected to the top flange of the frame member and presentinga fulcrum at the opposite end thereof; a second die-stamped sheet metallever having a depression seated on said fulcrum; a pair of coil springsarranged .on opposite sides of said frame member; a U-shaped bar havinghooked ends connected to one end of each of said springs and straddling`the lever at the end of the frame; said lever also having a depressionto receive said lil-shaped bar; a cross bar seated against the lever atthe opposite end of the frame; hook members connected to the other endsof said springs and having threaded Shanks screwed into the cross bar; alocking plunger in the frame cooperating with the channel-shaped memberto lock it in extended position and means whereby the locking plungermay be depressed to release the channel-shaped member and therebyrelieve the levers of the spring tension.

' ll. In combination with a reciprocating cutter bar having a cutterhead, a doubleacting recoil bui'ter including vertical levers arrangedin the path of the cutter head; and a pair of springs connected to thelevers so as to press them toward each other and absorb the shock of thecutter head on both strokes.

12. In combination with the cutter head otl a mowing machine, a recoilbu'er secured to the shoe above the cutter head; and a removable hoodfor the buffer detachably connected to the shoe and having an upwardlyand rearwardly inclined top wall to permit cut grain or grass -to slideover the top.

13. ln combination with the cutter bar of a mowing machine, a cutterhead; a doubleacting recoil bufl'erA mountedron the upper face of theslice above the cutter head and presenting a pair of short springpressed.

levers projecting downwardy into the path of the cutter head.

14e. A recoil butler for the cutter bar of' a mowing machine comprising,in combination a frame mounted on the shoe; a cutter head on the cutterbar; a pair of levers fulcrumed on thel opposite ends of the frame andhaving their free ends projecting downwardly into the path of the cutterhead; and tension springs operatively connected to the levers below andadjacent to their Jfulcrumed ends whereby the free ends of the leversmay move through a relatively wide range while eX- panding said springsthrough a short range.

ln testimony, that Iclaim the foregoing as my own, l have hereto afliXedmy signature.

NATHANrEL B. sroNE.

